compose-radar-map.ps1

# Compose a street map and weather radar into an image.
#
# Map GIS export from ArcGIS. Query f=html to view a sample exported image and form to tweak parameters.
# https://services.arcgisonline.com/arcgis/rest/services/World_Street_Map/MapServer/export?bbox=-15165054.230000%2C2294608.041000%2C-6778397.876000%2C6947666.110000&bboxSR=&layers=&layerDefs=&size=3440%2C1440&imageSR=102100&format=png32&transparent=false&dpi=&time=&layerTimeOptions=&dynamicLayers=&gdbVersion=&mapScale=&rotation=&datumTransformations=&layerParameterValues=&mapRangeValues=&layerRangeValues=&f=html
#
# Radar GIS export from NOAA.
# https://idpgis.ncep.noaa.gov/arcgis/rest/services/NWS_Observations/radar_base_reflectivity/MapServer/export?bbox=-15165054.230000%2C2294608.041000%2C-6778397.876000%2C6947666.110000&bboxSR=&layers=&layerDefs=&size=3440%2C1440&imageSR=102100&format=png32&transparent=true&dpi=&time=&layerTimeOptions=&dynamicLayers=&gdbVersion=&mapScale=&rotation=&datumTransformations=&layerParameterValues=&mapRangeValues=&layerRangeValues=&f=html
#
# Use the same bounding box, image spatial reference, and size for both requests so the layers align.
# I grabbed a reference continental US bounding box from https://digital.weather.gov/staticpages/mapservices.php:
# -15165054.230000,2294608.041000,-6778397.876000,6947666.110000.

mkdir -force work
mkdir -force final

$map = "work\conus-map.png"
$radar = "work\conus-radar.png"
$radarMapUpdate = "final\conus-map-radar1.png"
$radarMap = "final\conus-map-radar.png"

# Get the map only if it doesn't exist. This is a 9MB file and downloads slowly.
if (-not (Test-Path $map)) {
    Invoke-WebRequest -Uri "https://services.arcgisonline.com/arcgis/rest/services/World_Street_Map/MapServer/export?bbox=-15165054.230000%2C2294608.041000%2C-6778397.876000%2C6947666.110000&bboxSR=&layers=&layerDefs=&size=3440%2C1440&imageSR=102100&format=png32&transparent=false&dpi=&time=&layerTimeOptions=&dynamicLayers=&gdbVersion=&mapScale=&rotation=&datumTransformations=&layerParameterValues=&mapRangeValues=&layerRangeValues=&f=image" -OutFile $map
}

# Get the latest radar
Invoke-WebRequest -Uri "https://idpgis.ncep.noaa.gov/arcgis/rest/services/NWS_Observations/radar_base_reflectivity/MapServer/export?bbox=-15165054.230000%2C2294608.041000%2C-6778397.876000%2C6947666.110000&bboxSR=&layers=&layerDefs=&size=3440%2C1440&imageSR=102100&format=png32&transparent=true&dpi=&time=&layerTimeOptions=&dynamicLayers=&gdbVersion=&mapScale=&rotation=&datumTransformations=&layerParameterValues=&mapRangeValues=&layerRangeValues=&f=image" -OutFile $radar

# Compose to a temp file
# 1. Compose both images with the map as the base layer and add transparency on the radar layer
# 2. Annotate the date and time
$date = Get-Date -Format "dddd MM/dd/yyyy hh:mm tt"
& magick convert $map '(' $radar -normalize +level 0,60% ')' -compose over -composite -fill black -pointsize 52 -annotate +80+1280 $date $radarMapUpdate

# Update the main copy. Keep both copies because it seems like Windows sometimes doesn't switch
Copy-Item $radarMapUpdate -Destination $radarMap